Treatment for non-insulin dependent diabetes mellitus (Type 2 diabetes) usually consists of a regimen of diet and exercise, oral hypoglycemic agents and, in more severe cases, insulin. Oral agents common use are the sulfonylureas and biguanides. While the sulfonylureas are valuable for the treatment of Type 2 diabetes, they may give rise to hypoglycemic episodes and exhibit other toxic manifestations which limit their use. They are also prone to a high incidence of primary and secondary failures of efficacy. Similarly, the use of biguanides has declined because of their association with incidents of toxic lactic acidosis. A continuing need for new hypoglycemic agents which may be less toxic and more efficacious is clearly evident.
5-[(1-and 2-naphthalenyl)sulfonyl]-2,4-thiazolidinediones (Zask and Jirkovsky U.S. Pat. No. 4,997,948, 1991), 5-[(1-and 2-naphthalenyl)thio]-2,4-thiazolidinediones (Zask and Jirkovsky U.S. Pat. No. 5,068,342, 1991) and 5-[arylsulfonyl]-2,4-thiazolidinediones (Zask et al, J. Med. Chem. 1990, 33, 1418-1423) were previously disclosed as antidiabetic agents. The compounds of the present invention, (I), differ in that they also contain a 5-[3-aryl-prop-2-ynyl] group. This latter moiety enhances the antidiabetic potency of 5-arylsulfonyl-2,4-thiazolidinediones. 2-[(4-Methylphenyl)sulfonyl]-5-phenylpent-4-ynoic acid (BM13907), (A) (Wolff, et al. U.S. Pat. No. 4,933,367, 1990; Freund, et al. Arch. Pharmacol. 1989, 340 (suppl R40) Abstract 117; Obermaier-Kusser Biochem. J. 1989, 261,699) was also disclosed as antidiabetic agent. The compounds of the present invention, (I), differ in that they contain a 2,4-thiazolidinedione ring in place of a carboxyl group of A. ##STR2##
Other disclosures claim compounds which contain a 2,4-thiazolidinedione ring and also show antidiabetic activity. These include ciglitazone (U.S. Pat. No. 4,461,902; Sohda, et al. Chem. Pharm. Bull. 1982, 30, 3580) and a number of more potent analogs: pioglitazone (Sohda, et al. Arzneim.-Forsch./Drug. Res. 1990, 40, 37), englitazone (Stevenson, et al. Metabolism 1991, 40, 1268); CS-045 (Metabolism 1991, 40, 1213) and others (Hulin, et. al. J. Med. Chem. 1992, 35, 1853; Sohda, et al. J. Med. Chem. 1992, 35, 2617). None of the 2,4-thiazolidinedione containing compounds from the above disclosures contain the 5-(arylsulfonyl), 5-(arylsulfanyl) or 5-[3-aryl-prop-2-ynyl] groups possessed by the compounds of the present invention.
Compounds in which sulfur is attached to the 5-position of a 2,4-thiazolidinedione ring have been disclosed (Japan Kokai 78 40, 770; Japan Kokai 78 46, 973; Mikrobiol. Zh. (Kiev) 1970, 32, 518-520 (Ukrain); Ger. Offen.DE 3,045,059) but differ from the compounds of the present invention in that the nitrogen of the 2,4-thiazolidinedione ring is substituted or the sulfur is in the form of a sulfonic acid. In addition, these compounds are not sulfones and do not contain a napthalene ring. Furthermore, these compounds are claimed as having only antifouling or antibiotic properties.